It has the Yanmar ECU controlled, indirectly charged engine. Yanmar pioneered that swirl chamber process for smaller diesels making them more reliable and fuel efficient. No smoggies of any kind other than the ECU deciding what and when. Doesn't smoke, doesn't stink, starts in a flash, pulls like an Ox, sips diesel. I am overly happy with mine and I am picky. The design was very well thought out for operator convenience and room....like a tilt wheel on a 25 hp tractor???? I did add a suspension system to the upgraded seat that comes with it. Nice soft ride now.